The present invention relates to disc brakes and more specifically ventilated rotors or discs for disc brakes.
The recent demand for better fuel efficiency and weight reduction of motor vehicles involves the demand for more light-weight brake units.
For reducing the weight of a ventilated rotor (or disc) having two parallel discs, the reduction of wall thicknesses of the discs is effective. However, thin wall discs may adversely influence the heat absorbing performance and braking performance. In particular, this tendency is strong in front disc brakes which must bear 60.about.80% of the braking load of a vehicle.
Japanese Patent Kokai Publication No. 6(1994)-129452 and Japanese Patent Kokai Publication No. 8(1996)-74900 disclose ventilated rotors having tapered inside surfaces designed to improve the cooling efficiency.